Modulation and free-space link characteristics of monolithicallyintegrated vertical-cavity lasers and photodetectors with microlenses

摘要

We present temperature, modulation, and free-space linkncharacteristics of monolithically integrated vertical-cavity lasersn(VCLs) and resonant photodetectors. The devices have been integratednusing a novel structure that makes it possible to fabricate devices withnthrough-the-substrate emission and detection. Taking advantage of thensubstrate emitting/detecting architecture, we monolithically integratenmicrolenses on the substrate side of the devices and flip-chip bondnarrays without via processes or substrate removal. Low-thresholdnhigh-efficiency VCLs exhibit maximum small-signal modulation bandwidths,nwhich are limited by parasitics, of ~9.5 GHz at 20°C and ~8.4 GHz atn70°C. The VCLs have the lowest reported bias currents required tonreach bandwidths of up to ~8 GHz. A free-space optical link isndemonstrated with flip-chip-bonded arrays of microlensed, monolithicallynintegrated VCLs and detectors. The link is found to be tolerant tontemperature differences of ±75°C between the VCL andndetector, with error free (BER<10-12) data transmissionndemonstrated in each case